Three school children were killed and another was seriously injured in an explosion in Assam's Tinsukia district on Wednesday afternoon, a government official said.
Assam Home Secretary GD Tripathy said a schoolboy was killed on the spot and two children who were injured died while being taken to hospital.
"The blast took place near a lower primary school at Kharjan near Digboi today (Wednesday). A schoolboy, who received critical injuries in the blast, is being treated at a local hospital," Tripathy said.
A detailed report on the incident was awaited, he added.
About 550 km from Assam's capital Guwahati, Digboi is known as the state's oil township where crude oil was first discovered.
Tripathy said that there were inputs that the anti-talk faction of the United Liberation Front of Asom might try to carry out subversive activities in the district. "We are trying to find out if a militant outfit is behind the blast," he said.